1. Field of the Invention
The present invention relates to a sintered body assembly formed from a plurality of compacts which are prepared independently and joined together at the time of sintering and a method of producing such a sintered body assembly.
2. Description of the Prior Art
A method of producing a sintered body assembly of the above described kind is known as disclosed by Japanese provisional patent publication No. 60-11276. By this method, a plurality of independent compacts composed of inorganic powder or powders are prepared by cold isostatic pressing in such a way that the densities of the compacts approximate to each other. The compacts are assembled by cold isostatic pressing and thereafer subjected to firing or sintering.
A method of producing a turbine rotor is known as disclosed by Japanese provisional patent publicaton No. 55-75504. By this method, a compact for a rotor hub having at the outer periphery a plurality of grooves at a predetermined interval is prepared by hot pressing. A plurality of compacts for vanes are prepared by injection molding and fitted in the grooves of the compact for the hub. After assembly, the compacts are subjected to firing or sintering and formed into an integral body.
A problem of the prior art methods is that cracks, breakage, imcomplete joining, etc. are liable to occur in the products. This is because that the compacts to be assembled require a relatively strict approximation in density.
Another problem is that in case of the method disclosed by Japanese provisional publication No. 60-11276 a difficult process of subjecting the compacts to cold isostatic pressing is required after assembly. In case of the method disclosed by Japanese provisional patent publication No. 55-75504, cracks, incompete joining, etc. are liable to result from a relatively small error in the shrinkage percentage of the compacts for the hub and vanes.